Google has clarified why it recommends hyphens rather than underscores in URLs: hyphens mark word boundaries, while underscores have historically kept concepts together. For site owners, the change explains an existing preference rather than introducing a new ranking rule.

The October 23 documentation changelog says the revision brings the guidance into line with Google’s The Non-Canonical Cabinet video series. It announces no requirement to rename existing pages.

Underscores have a different history

Google’s URL structure guide points to programming conventions, where an underscore can keep a name such as format_date together. Hyphens provide a clearer boundary between words, helping people and search engines identify the concepts in an address.

Its examples favor /summer-clothing/ over /summer_clothing/ .…